Influencing factors analysis and prediction for oxygen-enriched combustion characteristics of municipal sludge

doi:10.16085/j.issn.1000-6613.2024-1235

Abstract

Abstract:

The underlying factors and mechanisms that influence the oxy-fuel combustion characteristics of municipal sludge remain largely elusive. Predictive and quantitative evaluation methods for these characteristics are currently lacking. In view of this, the influence of tube furnace preheating temperature, gas flow rate, and oxygen concentration on the combustion characteristics and temperature distribution within the reaction domain were investigated. A data-driven regression model for predicting the oxy-fuel combustion characteristics of sludge was developed and verified. The findings indicated that preheating temperature exerted the most substantial influence on the characteristics of sludge’s oxy-fuel combustion. As the preheating temperature rose from 873.15K to 1073.15K, the ignition delay time and ignition temperature of sludge decreased by 75% and 49%, respectively. The ignition delay time and ignition temperature exhibited an increase with the increase of gas flow rate, yet the rate of increase attenuated. In a high-temperature and oxygen-enriched atmosphere, an increment in oxygen concentration exerted minimal influence on oxygen-enriched combustion characteristics of sludge. At a preheating temperature of 1073.15K, the change in oxygen mass fraction from 0.3 to 0.8 led to a variation of 1.04s in sludge ignition delay time and 2.93K in ignition temperature. The regression model for sludge oxy-fuel combustion characteristics optimized by the genetic algorithm can accurately predicts sludge ignition delay time and temperature. The model’s predictions exhibited a relative error of less than 10% compared to numerical calculations and less than 15% compared to experimental data.

Key words: municipal sludge, oxygen-enriched combustion, combustion characteristics, numerical simulation, genetic algorithm, prediction

摘要：

市政污泥富氧燃烧特性的影响因素及影响规律尚不完全明确，富氧燃烧特性的预测及量化评估方法依然缺乏。针对此，本文研究管式炉预热温度、管式炉入口气体流量、氧气浓度对污泥燃烧特性及反应域内温度场分布状态的影响规律，提出了基于数据驱动的污泥富氧燃烧特性回归预测模型，并完成了模型的准确性验证分析。研究结果表明，预热温度对污泥富氧燃烧特性的影响最为显著。当预热温度从873.15K升高到1073.15K时，污泥的着火延迟时间和着火温度分别降低了75%和49%。着火延迟时间及着火温度均随着气体流量的增加而增大，上升幅度减缓。高温富氧氛围下，氧气浓度提升对污泥富氧燃烧特性的影响较小。预热温度为1073.15K、氧气质量分数在0.3~0.8范围内变化时，污泥着火延迟时间及着火温度的变化量分别为1.04s和2.93K。基于遗传算法优化的污泥富氧燃烧特性回归预测模型能够较准确预测污泥着火延迟时间及着火温度，模型预测结果与数值计算结果之间的相对误差整体小于10%，与试验测试结果之间的平均相对误差小于15%。

关键词: 市政污泥, 富氧燃烧, 燃烧特性, 数值模拟, 遗传算法, 预测

CLC Number:

X705

ZHANG Guanghui, JIANG Jinxu, HUANG Lei, CHEN Shixiang, MA Tiantian. Influencing factors analysis and prediction for oxygen-enriched combustion characteristics of municipal sludge[J]. Chemical Industry and Engineering Progress, 2025, 44(9): 5460-5470.

张光辉, 江金旭, 黄磊, 陈士祥, 马天添. 市政污泥富氧燃烧特性影响因素分析及预测[J]. 化工进展, 2025, 44(9): 5460-5470.

Figures/Tables 18

References 20

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工业分析^①（质量分数）/%					元素分析^①（质量分数）/%				低位发热量Q/MJ·kg^-1
C	H	O	N	S	挥发分	固定碳	灰分	水分	低位发热量Q/MJ·kg^-1
26.33	4.56	15.59	4.84	0.87	48.12	4.07	44.31	3.50	9.70

工业分析^①（质量分数）/%					元素分析^①（质量分数）/%				低位发热量Q/MJ·kg^-1
C	H	O	N	S	挥发分	固定碳	灰分	水分	低位发热量Q/MJ·kg^-1
26.33	4.56	15.59	4.84	0.87	48.12	4.07	44.31	3.50	9.70